Communicating Control Information in Mobile Communication System

1. A method for a receiver to receive control information via a physical control channel from a transmitter in a mobile communication system, the method comprising: receiving the control information via the physical control channel from the transmitter, wherein the control information comprises an indicator having a specific value selected from among a plurality of values, wherein each of the plurality of values, other than the specific value, is predetermined between the transmitter and the receiver to indicate each size of data to be received via a physical channel associated with the physical control channel, wherein the indicator having the specific value is used to inform the receiver of a specific situation that occurred at the transmitter, wherein the specific situation is related to a situation where the transmitter has transmitted data via the physical channel using only a part of available room of the physical channel for transmitting data and is unrelated to indicating each size of the data to be received via the physical channel by the indicator; and receiving data via the physical channel based on the identified situation.

2. The method of claim 1 , wherein the data is received in a form of a Medium Access Control Protocol Data Unit (MAC PDU).

3. The method of claim 1 , wherein the control information further comprises a transmission power related parameter.

4. A receiving end device for receiving control information via a physical control channel from a transmitting end device in a mobile communication system, the receiving end device comprising: an RF module including a transmitter and a receiver, wherein the receiver is configured to receive the control information via the physical control channel from the transmitting end device, wherein the control information comprises an indicator having a specific value selected from among a plurality of values, wherein each of the plurality of values, other than the specific value, is predetermined between the receiving end device and the transmitting end device to indicate each size of data to be received via a physical channel associated with the physical control channel, wherein the indicator having the specific value is used to inform the receiving end device of a specific situation that occurred at the transmitter, and wherein the specific situation is related to a situation where the transmitting end device has transmitted data via the physical channel using only a part of available room of the physical channel for transmitting data and is unrelated to indicating each size of the data to be received via the physical channel by the indicator; and a processing unit module coupled with the RF module, wherein the processing unit module is configured to identify that the specific situation occurred at the transmitter by using the received indicator having the specific value, wherein the processing unit module controls the receiver of the RF module to receive data via the physical channel based on the identified situation.

5. The receiving end device of claim 4 , wherein the data is received in a form of a Medium Access Control Protocol Data Unit (MAC PDU).

6. The receiving end device of claim 4 , wherein the control information further comprises a transmission power related parameter.